Shortly after the rollout of Microsoft’s Windows 10 update in April, some users complained about bugs — including Chrome and other apps like the Cortana personal assistant freezing. But there may be another problem for Microsoft to fix.

In a letter to the Denver Post, someone identified by the publication as “Jim W., from Flagler, Co.”, complained about the impact of a recent Windows 10 update on his five-year-old laptop:

“Microsoft pushed the big (monthly) update. It all but destroyed my laptop. I have a sign-in screen which then goes to the terrifying BBS. I have no icons, no tool bars, no Wi-Fi, no drivers, etc. I am using Ethernet for internet connection. The only way I can navigate is by going to task manager and right-clicking items that look like something. Fortunately, I did not lose any of my files.”

In a statement to Fortune, Microsoft suggested that the problem may impact users who have Avast antivirus. “In cooperation with Avast, we’ve identified a solution to ensure compatibility between the Avast Behavior Shield and our April 2018 Update,” Microsoft said. “Customers can learn more by visiting the following forum.”

The forum lists steps for users to take if they are running Avast and see a “‘choose your keyboard layout’ screen or [are brought] to a blank screen with a Recycle Bin,” after they’ve installed Windows 10 April 2018 update and restarted their computers.

Fortune followed up with Microsoft to see if this is what the company suspects happened to Jim W.’s computer or if it has confirmation that he was running Avast.

The Denver Post suggested that Jim W. visit a Microsoft store or for users to talk to other tech support groups. It also suggested trying the Windows 10 toolthat allows users to “start fresh with a clean installation of Windows 10.” (The U.K. publication the Express also mentions this as a solution.) Windows does warn that this tool will remove all non-standard apps “including other Microsoft apps such as Office,” and after using the tool you’ll have to manually download all of them again. This tool may also cause users to lose all of their digital licenses. (Microsoft provides recommendations about getting your license numbers and product keys before using the start fresh tool.)

The Windows 10 April 2018 Update is the fifth “major release” of Windows 10, according to Windows Central, and it was available to some systems on April 30, while others had to wait until May 9, tech news site The Verge reported. After the launch, some users complained on Reddit and other social media services about a series of problems (catalogued by Windows Central) including issues isolated to specific computers such as Dell’s Alienware.

Microsoft said it fixed the problems with Chrome and “Hey Cortana” freezing in a May 8 Windows update.